1. Field of the Invention
The present invention relates to an image-forming system for forming an image on an image-forming substrate, coated with a layer of microcapsules filled with dye or ink, by selectively breaking or squashing the microcapsules in the layer of microcapsules. Further, the present invention relates to such an image-forming substrate and an image-forming apparatus, which forms an image on the image-forming substrate, used in the image-forming system.
2. Description of the Related Art
An image-forming system per se is known, and uses an image-forming substrate coated with a layer of microcapsules filled with dye or ink, on which an image is formed by selectively breaking or squashing microcapsules in the layer of microcapsules.
For example, in a conventional image-forming system using an image-forming substrate coated with a layer of microcapsules in which a shell of each microcapsule is formed from a photo-setting resin, an optical image is formed as a latent image on the layer of microcapsules by exposing it with light rays in accordance with image-pixel signals. Then, the latent image is developed by exerting a pressure on the layer of microcapsules. Namely, the microcapsules, which are not exposed to the light rays, are broken and squashed, whereby dye or ink seeps out of the broken and squashed microcapsules, and thus the latent image is visually developed by the seepage of dye or ink.
Of course, in this conventional image-forming system, each of the image-forming substrates must be packed so as to be protected from being exposed to light, resulting in wastage materials. Further, the image-forming substrates must be handled such that they are not subjected to excess pressure due to the softness of unexposed microcapsules, resulting in an undesired seepage of dye or ink.
Also, a color-image-forming system, using an image-forming substrate coated with a layer of microcapsules filled with different color dyes or inks, is known. In this system, the respective different colors are selectively developed on an image-forming substrate by applying specific temperatures to the layer of color microcapsules. Nevertheless, it is necessary to fix a developed color by irradiation, using a light of a specific wavelength. Accordingly, this color-image-forming system is costly, because an additional irradiation apparatus for the fixing of a developed color is needed, and electric power consumption is increased due to the additional irradiation apparatus. Also, since a heating process for the color development and an irradiation process for the fixing of a developed color must be carried out with respect to each color, this hinders a quick formation of a color image on the color-image-forming substrate.
Therefore, an object of the present invention is to provide an image-forming system, using an image-forming substrate coated with a layer of microcapsules filled with dye or ink, in which an image can be quickly formed on the image-forming substrate at a low cost, without producing a large amount of waste material.
Another object of the present invention is to provide an image-forming substrate used in the image-forming system.
Yet another object of the present invention is to provide an image-forming apparatus used in the image-forming system.
In accordance with an aspect of the present invention, there is provided an image-forming system comprising an image-forming substrate that includes a base member, and a layer of microcapsules, coated over the base member, containing at least one type of microcapsules filled with a dye. A shell of wall of each of the microcapsules is formed of resin that exhibits a temperature/pressure characteristic such that, when each of the microcapsules is squashed under a predetermined pressure at a predetermined temperature, discharge of the dye from the squashed microcapsule occurs. The system further comprises an image-forming apparatus that forms an image on the image-forming substrate, and the image-forming apparatus includes a pressure applicator that locally exerts the predetermined pressure oh the layer of microcapsules, and a thermal heater that selectively heats a localized area of the layer of microcapsules, on which the predetermined pressure is exerted by the pressure applicator, to the predetermined temperature in accordance with an image-information data, such that the microcapsules in the layer of microcapsules are selectively squashed, and an image is produced on the layer of microcapsules.
In accordance with another aspect of the present invention, there is provided an image-forming system comprising an image-forming substrate that includes a base member, and a layer of microcapsules, coated over the base member, containing at least one type of microcapsules filled with a dye. A shell of wall of each of the microcapsules is formed of resin that exhibits a temperature/pressure characteristic such that, when each of the microcapsules is squashed under a predetermined pressure at a predetermined temperature, discharge of the dye from the squashed microcapsule occurs. The system further comprises an image-forming apparatus that forms an image on the image-forming substrate, and the image-forming apparatus includes an array of piezoelectric elements laterally aligned with each other with respect to a path along which the image-forming substrate passes. Each of the piezoelectric elements selectively generates an alternating pressure when being electrically energized by a high-frequency voltage, and the alternating pressure has an effective pressure value that corresponds to the predetermined pressure. The apparatus further includes a platen member that is in contact with the array of piezoelectric elements, and an array of heater elements provided on the respective piezoelectric elements included in the array of piezoelectric elements, each of the heater element being selectively heatable to the predetermined temperature.
In accordance with yet an aspect of the present invention, there is provided an image-forming system comprising an image-forming substrate that includes a base member, and a layer of microcapsules, coated over the base member, containing at least one type of microcapsules filled with a dye. A shell of wall of each of the microcapsules is formed of resin that exhibits a temperature/pressure characteristic such that, when each of the microcapsules is squashed under a predetermined pressure at a predetermined temperature, discharge of the dye from the squashed microcapsule occurs. The system further comprises an image-forming apparatus that forms an image on the image-forming substrate, and the image-forming apparatus includes a platen member laterally provided with respect to a path along which the image-forming substrate passes, a carriage that carries a thermal head, movable along the platen member, a resilient biasing unit incorporated in the carriage to press the thermal head against the platen member with the predetermined pressure, and a resilient biasing unit incorporated in the carriage to press the thermal head against the platen member with the predetermined pressure. The thermal head selectively heats a localized area of the layer of microcapsules, on which the predetermined pressure is exerted by the resilient biasing unit, to the predetermined temperature in accordance with an image information data, such that the microcapsules included in the layer of microcapsules are selectively squashed and an image is produced on the layer of microcapsules.
In accordance with still yet an aspect of the present invention, there is provided an image-forming substrate comprising a base member, and a layer of microcapsules, coated over the base member, containing at least one type of microcapsules filled with a dye, wherein a shell of wall of each of the microcapsules is formed of resin that exhibits a temperature/pressure characteristic such that, when each of the microcapsules is squashed under a predetermined pressure at a predetermined temperature, discharge of the dye from the squashed microcapsule occurs.
Preferably, the layer of microcapsules is covered with a sheet of protective transparent film. The base member may comprise a sheet of paper. Optionally, the base member comprises a sheet of film, and a peeling layer is interposed between the sheet of film and the layer of microcapsules.
The resin of the shell wall may be a shape memory resin, which exhibits a glass-transition temperature corresponding to the predetermined temperature. Also, the shell wall, formed of the shape memory resin, may be porous, whereby an amount of dye to be discharged from the shell wall is adjustable by regulating the predetermined pressure.
Also, the shell wall of the microcapsules may comprise a double-shell wall. In this case, One shell wall element of the double-shell wall is formed of a shape memory resin, and the other shell wall element thereof is formed of a resin, not exhibiting a shape memory characteristic, such that the temperature/pressure characteristic is a resultant temperature/pressure characteristic of both the shell wall elements.
Further, the shell wall of the microcapsules may comprise a composite-shell wall including at least two shell wall elements formed of different types of resin, not exhibiting a shape memory characteristic, such that the temperature/pressure characteristic is a resultant temperature/pressure characteristic of the shell wall elements.
The layer of microcapsules may include a first type of microcapsules filled with a first dye and a second type of microcapsules filled with a second dye. A first shell wall of each of the first type of microcapsules is formed of a first resin that exhibits a first temperature/pressure characteristic such that, when the shell wall is squashed under a first pressure at a first temperature, discharge of the first dye from the squashed microcapsule occurs. A second shell wall of each of the second type of microcapsules is formed of a second resin that exhibits a second temperature/pressure characteristic such that, when the shell wall is squashed under a second pressure at a second temperature, discharge of the second dye from the squashed microcapsule occurs. Preferably, the first temperature is lower than the second temperature, and the first pressure is higher than the second pressure.
Also, the layer of microcapsules may include a first type of microcapsules filled with a first dye, a second type of microcapsules filled with a second dye, and a third type of microcapsules filled with a third dye. A first shell wall of each of the first type of microcapsules is formed of a first resin that exhibits a first temperature/pressure characteristic such that, when the shell wall is squashed under a first pressure at a first temperature, discharge of the first dye from the squashed microcapsule occurs. A second shell wall of each of the second type of microcapsules is formed of a second resin that exhibits a second temperature/pressure characteristic such that, when the shell wall is squashed under a second pressure at a second temperature, discharge of the second dye from the squashed microcapsule occurs. A third shell wall of each of the third type of microcapsules is formed of a third resin that exhibits a third temperature/pressure characteristic such that, when the shell wall is squashed under a third pressure at a third temperature, discharge of the third dye from the squashed microcapsule occurs. Preferably, the first, second and third temperatures are low, medium and high, respectively, and the first, second and third pressure are high, medium and low, respectively.
Preferably, the first, second, and third dyes exhibit three-primary colors, for example, cyan, magenta and yellow, respectively. In this case, the layer of microcapsules may further include a fourth type of microcapsules filled with a black dye. A fourth shell wall of each of the fourth type of microcapsules may be formed of a resin that exhibits a temperature characteristic such that the fourth shell wall plastified at a fourth temperature which is higher than the first, second and third temperatures. Optionally, the fourth shell wall may be formed of another resin that exhibits a pressure characteristic such that the fourth shell wall is physically squashed under a fourth pressure which is higher than the first, second and third pressures.
Furthermore, the present invention is directed to various image-forming apparatuses, one of which is constituted so as to produce an image on any one of the above-mentioned image-forming substrates, as stated in detail hereinafter.